Filter



April 1936- R P F. LIDDELL ET AL FILTER aiv r-iginal Filed Dec. 11, 1930 2 Sheets-Sheet l al 1 I v BY 5 material filtered from the Patented Apr. 21, 1936 UNITED STATES ample 7 Robert P. F. Liddell, Darlen, Conn an Inn 7 W. Williams, Morris Township, Mo

rria County,

N. J., assignors to Motor Improvements, 1110., Newark, N. J., a corporation of Delaware Application Decemberll, 1930, Serial No. 501,558

Renewed March 1, 1934 I 15 Claims.

This invention relates to filters and has for an object an improved filter having provision for directing filtered fluid reversely through the filter unit for the purpose of removing therefrom solid fluid and collected by the filtering unit.

A filter embodying this invention comprises a casing which is divided into inlet and outlet sections by a filtering unit. Manually operable 10 means are provided for decreasing the capacity of the outlet section and increasing the capacity of the inlet section to cause filtered fluid to flow reversely through the filtering unit without any change in the contents of the casing, the reverse 15 flow being effective to remove the filter cake from the filter unit. Preferably, the filtering unit comprises a metal cylinder having a large number of narrow slots, the cylinder surrounding and being supported by a fluted drum. The flutes in the 20 drum form channels communicating with the interior of the drum and through which the filtered oil is conducted. Within the drum there is provided a tube having communication both with the interior of the .drum. and with the inlet section of the casing. This tube is provided at the end ciimmunicating with the inlet section with a closure and manually operable means are provided for moving such closure longitudinally of the tube. Such movement of the closure decreases the capacity of the outlet section and increases the capacity of the inlet section so that filtered fluid is forced reversely through the filtering cylinder and unfiltered oil follows the closure into the tube. Return of the closure to its original position restores the normal capacities of the two sections and the tube is again filled with filtered oil. v

In such'a filter, the filter unit is cleaned without change in the contents of the casing. Fur- 40 thermore, the cleaning of the filtering unit is eil'ected without any loss of filtered or unfiltered fluid. Y

Other objects, novel features and advantages of this invention will be apparent from the following specification and accompanying drawings, wherein:

Fig. 1 is a vertical section through one embodiment of the invention;

Fig. 2 is an enlarged section on" the line 2-2 0 of Fig. 1, and

Fig. 3 is a vertical section through a modified form of the invention. In Fig. 1, i0 is a base to which a shell is attached by means of an annular nut I! to form a 5 casing. A cup-shaped sheet metal member II has portions of three diiierent diameters and the portion of smallest diameter projects into a well Illa for med l ixl he. A-tub'e .l 4,1 has-its lower end fitted into thepoi tiouof interniediate diameter and resting Yup'on tongues; li-bent' inwardly from the wall o1 said portion. Aflu'ted drum l6 has its lower end extending into the largest diameter portion of the cup wall of the drum there is through which the tube l4 extends, the edge of this opening being serrated. In the top wall of the drum Hi there is providedan ofiset portion ll into which the upper end of the tube l4 projects. The upper end of the drum it engages the wall of the casing H by which the drum is held firmly in position.

A metal filtering unit i8 surrounds thedrum it from its upper end down to the rim of the cup' l3. This filtering unit comprises a cylinder comprising a helix wound from a thin metal ribbon with the wide faces normal to the axis of the helix, the ribbon being preformed with definite curvature so that its turns lie smoothly in contact with each other. This ribbon is of minute thickness and is provided at intervals with spaced ribs II which space apart the adjacent turns and form filtering slots through whichthe fluid to be flltered is passed. The ribbon preferably is approximately .045 inch wide and .006 inch thick while the ribsare preferably .001 to .002 inch in height.

A tube l9 passes through and is supported by the smallest diameter portion of the cup l3 and extends nearly to the upper end of the tube H. A sleeve 20 fits over the tube Hand is slidably mounted and sealed in a fitting 2!, a handle 22 being provided at the end of the sleeve. To the lower end of the sleeve 2| there is attached a pump plunger 23 which may be reciprocated in a tube It by in and out movement of the sleeve 20. At the lower end of the sleeve 20 is attached a member having arms 24 which are adapted to underlie the tongues l5 and lock the sleeve in the position shown in Fig. l. Rotation of the sleeve 20 disengages the arms from the tongues and permits operation of the sleeve. In the upper end of the tube 14 there is providedan aperture 25 and also an aperture 26 is provided in the upper part of the sleeve 20. An inlet channel 21 is provided in the base for conducting fluid tobe filtered into the space between the filter unit and the casing wall and an outlet 28 is provided in the base for discharging the filtered fluid.

The filter may be connected in any filtering system by means of suitable pipes. Preferably,

I3 and in the bottom provided an opening' the filter is used in connection with the lubrication system of an internal combustion engine and the crank case 011 is passed through the filterfor the purpose of removing contaminating material in the oil.

The incoming oil is delivered into the space between the filtering unit and the casing from whence it flows through the slots in the cylinder l3 into the channels formed by the flutes in the drum, these channels communicating with the chamber formed by the bottom wall of the drum and the member 15. The serrated edge of the aperture in the bottom wall oi the drum 16 provides a passageway through which the filtered fluid flows into the interior of the drum. The filtered fluid flows from the interior of the drum through the aperture 25 into the tube II to fill it up and from the tube H through the aperture 26 into the tube l9, through said tube into the well Illa. and then out through the outlet 23. The foreign material in the oil is collected on the surface of the cylinder i3 and, at any time that oil is not being supplied to the filter,

the filtering unit may be cleaned by causing reverse fiow oi. filtered fluid through such unit. This is accomplished by upward pull on the han dle 22 which through the medium of the sleeve 20 lifts the plunger. 23 and displaces the oil in the cylinder above the plunger through the aperture 25. The displaced oil flows downwardly around the tube l4 and upwardly through the channels formed by the flutes and then reversely through the slots in the cylinder 13. Such fiow' of oil is permitted due to the fact that the unfiltered oil in the casing is permitted to flow into the tube l4 through the apertures produced in the striking up of the tongues 25. with this arrangement, there is no change in the hontents of the filter, but sufilcient reverse fiow is estab lished to remove the filter cake from the filter unit. Upon return oi the plunger 23 to its original position, the unfiltered oil will be forced out of the tube I4 and back into the space between the filter unit and'the casing, and the cylinder ll will be again filled with filtered oil. This op eration may be repeated several times if desir able, or necessary.

In the modification disclosed in Fig. 3, 30 is a head to which a shell II is attached by means of a collar carried by clamps, not shown. The head is provided with an inlet passage 33 and an outlet passage 34. A fiuted drum 35 has two offset portions and a tubular fitting 38 passes through the portion of smaller diameter and is threaded into the head to attachythe "drum thereto. Within the drum 35 there is provided a tube 31 having its upper end fitting into the second ofiset portion of the top oi the drum.

A cup-shaped member 33 receives the lower end oi the drum 35 and between the upper edge of this member and the top of the drum there is arranged acylindrical filtering unit 39 formed of a helix wound from flat metal ribbon having projections, the member 33 being held in place by screws 40. The cylinder 31 extends through an aperture in the bottom wall of the drum 35, this aperture being iormed with a serrated edge. The channels iormed by the flutes in the drum communicate with the chamber formed between the bottom wall of the drum 35 and the cupshaped member 38 and this chamber communicates with the interior of the drum through the passageway formed by the serrated edge of the aperture through which the tube 31 extends. An aperture 4| in the upper end of the tube 31 provides communication between the interior oi the drum and the interior of the tube 31. A rod 42 is slidably mounted in a fitting 420 provided in the head 30 and is equipped with a handle 43.

the rod 42 and is provided with arms 46 which are adapted to underlie arms 41 projecting inwardly from the bottom of the tube 31, thereby locking the plunger. The arms may be disengaged by rotating the rod 42.

Oil to be filtered is introduced through the inlet 33 into the .spacebet-ween the filter unit and the casingwall and after passing through the slots in the filter unit fiow down the channels into the chamber between the bottom wall of the drum and the cup-shaped member 38. From this chamber, it flows upwardly around the tube 31 through the aperture 4|, fiows up the tube 31 and then flows out through the nipple 36 and outlet passage 34.

The cake collecting on the exterior surface of the filter unit 39 is removed by reverse flow of oil vthrough the filter unit in a manner similar to that described in the modification shown in Fig. l. Upward movement of the plunger 44 causes filtered oil to flow from the tube 31 through the aperture 4| into the interior of the drum 35 and then through the channels formed by the flutes and outwardly through the slots in the filter unit 39, while unfiltered oil flows upwardly into the tube 31 to permit the reverse flow just referred to. The return of the pump plunger 44 to its original position also returns the oil to the position from which it was displaced.

It is of course apparent that various modifica tions may be made in the structure above described, without in any way departing from the spirit of the invention as defined in the appended claims.

We claim:

1. In a filter, a casing, means including one or more fixed, rigid filtering units dividing said casing into inlet and outlet sections, and means for reducing the capacity of the outlet section and increasing the capacity of the inlet section to effect reverse flow of filtered fiuid through said unit.

2. A filter comprising a casing, means including a fixed, rigid filter unit dividing said casing into inlet and outlet sections, and reciprocating plunger means for reducing the capacity of said outlet secti i and increasing the capacity of said inlet secti' to effect reverse fiow of filtered fluid through the filtering unit.

' 3. A filter comprising a casing, a cylindrical filtering unit within said casing, a tube arranged within said filtering unit and communicating with the interior oi the filtering unit and with the space between the filtering unit and the casing wall, an inlet communicating with said casing, an outlet communicating with said tube, and a plunger mounted in said tube for reciprocation to effect reverse flow oi filtered fiuid through said filtering unit.

4. A filter comprising a casing having an inlet, fluted drum supported in said casing, a metal cylindrical filtering unit surrounding said drum and forming channels with said flutes, a cap fitting over one end of said drum and forming therewith a chamber communicating with said channels and with the interior oi said drum, a tube arranged within said drum and communicating with the interior of said drum and with'the space between the casing wall and the filtering unit, a plunger reciprocally mounted in said tube, said tube being, in communication with said outlet.

5. A filter comprising a casing, a fixed, rigid filtering unit within said casing dividing 'the same into inlet and outlet sections, and manually operable means for reducing the capacity of the outlet section and increasing the capacity of the inlet section to effect reverse flow oi filtered fluid through said-unit.

6. A filter comprising a casing, a fixed, rigid filtering unit'within said casing dividing the same into inlet and outlet sections, and manually operable means for forcing filtered fluid reversely through said filtering unit without reduction in the volume 01' fluid in the casing.

7. In afilter, a casing, a filtering unit dividing said casing into inlet and outlet sections, a passageway communicating with said inlet and outlet sections, and a closureior said passageway, said closure being movable in said passageway to cause filtered fluid to fiow reversely through said unit without change in the contents of said cas- 8 A filter comprising a casing, a cylindrical filtering unit within said casing, a tube communicating with the interior of said filtering unit and with; the spaceb etween the filtering unit and said casing, and a reciprocating piston mounted in said tubev for causing filtered fluid to fiow reversely through said unit without change in the contents oi the casing.

9. A filter comprising a casing, a hollow support within said casing, a filtering member surrounding said support, said support being provided with passageways to conduct filtered fluid into the interior thereof, a tube within said support communicating with the interior thereof and with the space between the filter member and the casing, and a plunger slidably mounted in said tube.

10. A filter comprising a casing, a slotted cylinder, a hollow support surrounded by said cylinder and having passageways for conducting filtered fluid into the interior thereof, a tube communicating at one end with the interior of said support and at the other end with the space between said cylinder and casing, and a piston slidably mounted in said tube.

11. A filter comprising a casing, a slotted cylinder, a hollow support surrounded by said'cylinder and having passageways for conducting filtered fiuid into the interior thereof, a tube arranged within said support, and a piston slidably mounted in said tube, said tube being in communication at one end with the space between the tube and said support and at the other end with the space between the cylinder and the casing. 12. A filter comprising a casing, a slotted cylinder, a fluted cylindrical drum surrounding by said cylinder, a cap forming with the end of said drum a chamber communicating with the flutes, a tube within said drum, said tube being in communication at one end with the space between it and the drum and at the other end with the space between the cylinder and the casing, a piston slidably mounted in said tube, and a passageway connecting said chamber with the space between said tube and drum.

13. A filter comprising a fluted drum, a slotted cylinder surrounding said drum, a cap fitting over one end of said drum and formingtherewith a 'chamber communicating with said flutes, a tube arranged within said drum, said tube being supported at one end by said cap and passing through an aperture in the end of the drum, clearance being provided between the edge of said aperture and the tube, and a plunger slidably mounted in said tube, said tube being in communication at one end with the interior of said drum and at the other end with the space surrounding said drum.

14. A filter comprising a fluted drum, a slotted cylinder surrounding said drum, a cap fitting over one end of said drum and forming therewith a chamber communicating with said flutes, a tube arranged within said drum, said tube being supported at one end by said cap and passing through an aperture in the end oi the dmm, clearance being provided between the edge of said aperture and the tube, a plunger slidably mounted in said tube, said tube being in communication at one end with the interior or said drum and at the other end with the space surrounding said drum, and an outlet leading from the interior of said tube, and an inlet communicating with the space exterior of said drum. I

15. A filter comprising a casing, a slotted cylinder, a hollow support surrounded by said cylinder and having passageways for conducting filtered fluid into the interior thereof, a tube communicating at one end with the interior of said support and at the other end with the space between said cylinder and easing, a'piston slidably mounted in said tube, an inlet for supplying fiuid to be filtered, and an outlet for discharging filtered fluid.

' ROBERT P. F. LIDDELL.

LEWIS W. WILLIAMS. 

